Note: Descriptions are shown in the official language in which they were submitted.
CA 02235835 1998-04-24
/
2776B ~
TT.F,
Hydrocarbon Stream Antifoulant Method Using Bridged Alkyl Phenates
RACK(;ROlJNn OF T~ YF,NTI'QN
S The presellt invention relates to a method for eontrolling the formation of
fouling deposits in a hydrocarbon process stream during processing thereof at
elevated te-llpc~alures
Fouling of tubes and cqui~ment carrying ref.llelr and petrochemical
process slrc~lls, particularly heated SllC,~.S, iS a general problem which has
great impact on process economics. Certain crude oils and other feedstocks
derived from crude oil, such as atmospheric pipestill residuum, catalytic cracker
residuum, vacuurn disti}lation residuum, as well as gas, oils, reformer stocks,
and chlorinated hydrocarbons are of concern in this regard. Thus, whenever
crude oils or other such materials are he~teti especially in heat exchanger and
furnace eq~-ip,nellt, deposits including asphaltenes and coke-like materials canform. This fouling can lead to problems such as reduced run times, reduced
conversions, increased energy requirell,cllts, shorter m~inten~nce cycles, and
increascd feed preheat losses. Antifoulants, which minimi7e such problems, are
therefore an im~ollant additi~e in many l~fillc.~ pr~cesses.
Fouling can also be a problem to be avoided in refinery streams involved
in processin~ and manufacture of ~lk~}es such as ethylene and propylene, for
instance, deeth~ni~pr bottoms. As used herein, the general term "hydrocarbon
process stream" enco...p~sses rer~ process streams, petroleum process
streams, and such alkene process ~ a~s, as well as other industrial process
streams of a predomir~o~ntly hydrocarbon nature which are subject to such
fouling. The use of the term "hydiocallJon process stream" is not intended to
indicate that hydrocarbons are the sole component of such stream or that hydro-
carbons are l~Gess~ ;ly the source of the fouling.
In the processin~ of such petroleum hydrocarbons and feed stocks, the
materials are commonly heated to ten~pclalul~s of 409C to 550~C, frequently
from 200~C to 550~C. Similarly, such petroleum hydrocarbons are frequently
employed as he~ting media on the "hot side" of he~in~ and heat exchange
systems. In many cases, such petroleum hydrocarbons contain deposit forming
compounds or constituents that are ~lcse~l before the processin~ is carried out.Examples of such preexisting deposit-forming materials are alkali and alkaline
earth metal-col-lAi~ compounds, e.g., sodium chloAde; transition metal
compounds or complexes, such as porphyrins or iron sulfide; sulfur-containg
.
CA 02235835 1998-04-24
co~ ,uulIds,~sucfi~as ~ p~ s; ~ltrogen-con~Ail~in~ compounds such as pyr-
roles; c&ll,ollyl or carboxylic acid-col-~A;ni~e compounds; polynuclear aromaticcompounds, such as ~fph~ltÇn~S; and eoke partieles. These deposit-forming
compounds can eombine or reaet during elevated t~ ra~ processing to
S produce a sep~dte phase known as fouling deposits, within the petroleum
hydrocarbon.
It is known to reduce fouling of process streams by injecting into such
streams certain anti-fouling additives, the principal components of which are
ofeen disyeljdnts or dele~ents, but which may also contain minor amounts of
10 antioxidants corrosion inhibitors, or metal deactivators or coordinators. These
additives are believed to act by slowing the fouling reaction rate and dispersing
any deposit-forming species p~esent in the stream
A variety of antifoulants are known U S Patent 2,760,852, Stevens et
al., Aug. 28, 1956, discloses the calcium salt of the con~en~ntion product of
15 formaldehyde ant an octyl phenol in a fuel compositiûn.
U.S. Patent 5,100,531, Steph~-ngo~ et al., March 31, 1992, discloses the
use of strearns of alkyl-substituted phenol form~lde~yde liquid resins in combi-nation with hydrophilic-lipophilic vinylic polymers (e.g., acrylate fatty ester
polymers) as an antifoulant for asphalt or asphaltene cont~inin,~ crude oil
20 streams.
U.S. Patent S,021,498, Steph~ c~- et al., June 4, 1991, discloses an
asphaltlasphaltene disl)e.sal~t comprising a mixture of an alkyl substituted
phenol formaldehyde liquid resin and a hydrophilie-lipophilic vinylic polymer.
U.S. Patent 3,035,908, Gottshall et al., May 22, 1962, discloses an
25 addition produet of an olefin oxide and a salfide~modified con-lç~tion product
of an Zllip}l~tiC aldehyde and a subslilu~ed monohydric phenol as a gasoline
motûr fuel additive.
U.S. Patent 3,657,133, Miller, April 18, 1972, tiscloses an oil soluble
~lk~line earth metal salt of a con~enQPt;ûn produet of an alkyl phenol and an
30 aldehyde as a co~ ol~ent in a funetional fluid.
SUM~RY OF THF. Il~VF~TION
The presel~t invention provides a method for controlling the formation of
fouling dep~sils in a hydroc~t~on process stream during processin~ thereof at
elevated te.ll~c.d~ s, comprising including in said hydroearbon process stream
35 an antifouling amount of a salt of a hy~oc~~ sllhstilut~ linked hydroxyaro-
matic co~l)~d, said linked col~o~d comprising at least two aromatic
moieties.
CA 02235835 1998-04-24
F.TATT.~T3F.~C~TeT~ON n~ T~. INVF.l~TION
rhe ~ cipal col~ncnt of t~e p~Sellt invention is a salt of a hydrcar-
byl-sul~litul.,d linked h.~ro"~olllatic coln~o,md. Hydrocarbyl-subs~ ted
aromatic compounds, also rc~llcd to as hy~c~l,~l-subsituted phenols are
S known materials, as is their method of prepaldtion. When the term "phenol" is
used herein, it is to be ~nte.3lood that this term is not generally intended to
limit the aromatic group of the phenol to be~ ne (unless the context so indi-
cates, for instance, in the Examples), although ~ & may be the preferred
aromatic group. Rather, the term is to be understood in its broader sense to
10 include hydroxy aromatic compounds in general, for example, substituted
phenols, hydroxy naphthalenes, and the like. Thus, the aromatic group of a
"phenol" can be mononuclear or polynuclear, su~stil.~ted, and can include other
types of aromatic groups as well.
The aromatic group of the hydrol~a~ atic compound can thus be a
15 single aromatic nucleus such as a be~el~e nucleus, a pyridine nucleus, a thio-
phene nucleus, a 1,2,3,4-tetrahyd.o~ h~lçrle nucleus, etc., or a polynuclear
aromatic moiety. Such polynuclear moieties can be of the fused type; that is,
wherein pairs of aromatic nuclei m~king up the aromatic group share two points,
such as found in naphthalene, al~tLacene, the azanaphthalenes, etc. Polynuclear
20 aromatic moieties also can be of the linked type ~hc.~,in at least two nuclei(either mono or polynuclear) are linked through bridging linkages to each other.Such bridging linkages can be chosen from the group consisting of carbon-to-
carbon single bonds between aromatic nuclei, ether linkages, keto linkages,
sulfide linkages, polysulfide linkages of 2 to 6 sulfur atoms, sulfinyl linkages,
25 sulfonyl linkages, methylene linkages, alkylene linkages, di-(lower alkyl)
methylene linkages, lower alkylene ether linkages, alkylene keto linkages, loweralkylene sulfur linkages, lower alkylene polysulfide linkages of 2 to 6 carbon
atoms, amino linkages, polyarnino linkages and mixtures of such divalent
bridging linkages. In certain instances, more than one bridging linkage can be
30 I)res~nt in the aromatic group between aromatic nuclei. For example, a fluorene
nucleus has two benzene nuclei linked by both a methylene linkage and a
covalent bond. Such a nucleus may be considered to have 3 nuclei but only two
of them are aromatic. Normally, the aromatic group will contain only carbon
atoms in the aromatic nuclei per se; although other non-aromatic substitution,
35 such as in particular short chain alkyl substitution can also be present. Thus
methyl, ethyl, propyl, and t-butyl groups, for instance, can be prcsent on the
CA 02235835 1998-04-24
aromatic-grou-~s, even t~gh such groups may not be explicitly represented in
structures set forth herein.
Specific examples of single ring aromatic moieties are the following:
cO(Et),~OH ~M
~Me ~)CCI ~C
CH ~ N
etc., wherein Me is methyl, Et is ethyl or ethylene, as al,prop.;ate, Pr is n-
propyl, and Nit is nitro.
CA 02235835 1998-04-24
-S~ecif,~ ple~f-fused r-ng aromatic moieties are:
~= ~c O(EtO~nH
MeO
Me ~Me Me ~ NO2
~ MeO~
etc.
When the aromatic moiety is a linked polynuclear aromatic moiety, it can
be rcpresente~l by the general formula
ar(--L--ar )w
wherein w is an integer of 1 to about 20, each ar is a single ring or a fused ring
aromatic nucleus of 4 to about 12 carbon atoms and each L is independently
selected from the group coneistinp of carbon-to-carbon single bonds between ar
20 nuclei, ether linkages (e.g. -O-), keto linkages (e.g., -C(=O~-), sulfide linkages
(e.g., -S-), polysulfide linkages of 2 to 6 sulfur atoms (e.g., -S-2 6)~ sulfinyl
linkages (e.g., -S(O)-), sulfonyl linkages (e.g., -S(O)2-), lower alkylene linkages
(e.g., -CH2-, -CH2-CH2-, -CH2-CHR~-), mono(lower alkyl)-methylene linkages
CA 02235835 1998-04-24
(e.g., -e~R~-~, di~rower~~kyl)-met~ylene linkages (e.g.,-CR~2-), lower alkylene
ether linkages (e.g., -CH20-, -CH20 CH2-, -CH2~CH20-, ~CH2CH20CH2CH-2,
-CH2CHR~-OCH2CH-, -CHR~-O-, -CHR~-O-CHR~-, -CH2CHR~-O-CHR~-CH2-,
etc.), lower alkylene sulfide linkages (e.g., wherein one or more -O-'s in the
5 lower alkylene ether linkages is replaced with a S atom), lower alkylene poly-sulfide linkages (e.g., wherein one or more -O- is replaced with a -S 2 6 group),
amino linkages (e.g., -NH-, -NR~-, -CH2N-, -CH2NCH2-, -alk-N-, where alk is
lower alkylene, etc.), polyamino linkages (e.g., -N(alkN)l 10~ where the unsat-
isfied free N valences are taken up with H atoms or R~ groups), linkages derived10 from oxo- or keto- carboxylic acids (e.g.)
R2 o
R1 1 C--C oRB
~C/ I
¦ ~ R x
wherein each of Rl, R2 and R3 is independently hydrocarbyl, preferably alkyl
or alkenyl, most preferably lower alkyl, or H, R6 is H or an alkyl group and x is
15 an integer ranging from ~0 to about 8, and ~ es of such bridging linkages
~each R~ being a lower alkyl group).
Specific examples of linked moieties are:
o$c
~CH~
CA 02235835 1998-04-24
~$
Me \ Me
/ 1--10
5 ~(ee~-
~\~ / '
1 -10, etc
Usually all of these aromatic groups have no substituents except for
those specifically named. For such rcaso~s as cost, availability, performance,
etc., the arol~atic group is normally a ~l~ene nucleus, a lower alkylene bridgedb~n7ene nucleus, or a n~rhth~lPne nucleus. Most preferably the aromatic group
is a single be~e~e nucleus.
This ~ y component, being a salt of a hydrocarbyl-subsliluted linked
hydro~ya.oll,atic compound, can thus be a conden~tion product of a hy-
droxyaromatic co,llpound, that is, a compound in which at least one hydroxy
group is dilectl~ ~tt~c.he~ to an aromatic ring. The number of hydroxy groups
per aro,llatic group will ~ary from 1 up to the maximum number of such groups
20 that the hy-l~ocd~ l-subsliLuled aromadc moiety can accommodate while still
ret~inin~ at least one, and preferably at least two, positions, at least some ofwhich are preferably adjacent (ortho) to a ~ydro~y group, which are suitable forfurther reaction by contlPn~tion with a suitable m~tPti~l such as an aldehyde
(described in detail below). ThUJ most of the molecules of the reactant hy-
CA 02235835 1998-04-24
drox~'matic~compou~ia~ll have at~least two unsubstituted positions. Suit-
able materials can include, then, hydrocarbyl-substituted catechols, resorcinols,
hydroquinones, and even pyrogallols and phloroglucinols. Most commonly each
aromatic ~nucleus, however, will bear one hy~ l group and, in the preferred
S case when a hydrocarbyl su~stituted phenol is employed, the material will
contain one b&-~7~l e nucleus and -one hydroxyl group. Of course, a small
fraction of the aromatic reactant molecules may contain zero hydroxyl substitu-
ents. For instance, a minor amount of non-hydroxy materials may be present as
an hllp~ y. However, this does not defeat the spirit of the inventions, so long
10 as the starting material is funcdonal and contains, typically, at least one hy-
droxyl group per molecule.
The hydroxyaromatic reactant is similarly characterized in that it is
hydrocarbyl substilulcd. The term- "hydrocarbyl substituent" or "hydrocarbyl
group" is used herein in its ordinary sense, which is well-known to those skilled
lS in the art. Speeifically, it rcfers to a group having a carbon atom directly
attached to the reln~inder of the molecule and having predonnin~ntly hydrocar-
bon character. Examples of hydloc~lJyl groups include:
(1) hydroc&lbon ~sliluents, that is, ~irh~tic (e.g., alkyl or alkenyl),
alicyclic (e.g., cycioalkyl, cycloalkenylj su~lil..eRls, and aromatic-, aliphatic-,
and alicyclic-su~.,lilu~d ar~n~alic ~u~sLI~.cnls, as well as cyclic substituentswherein the ring is completed through another portion of the molecule ~e.g., twosubstituents together form an alicyclic radical~;
(2) su~slilutcd hydrocarbon subs~ .c.lts, that is, substituents cont~ining
non-hydrocarbon groups which, in the Col~t~,cL of this invention, do not alter the
predo.~ tl~ hydrocarbon substituent (e.g., halo (especially chloro and
fluoro), hydroxy, aLkoxy, lllercal,lo, all~ll~rcapto, nitro, nitroso, and sulfoxy);
(3) hetero substituents, that is, substiluents which, while having a pre-
domin~nSly hydrocarbon~character, in the co~te~l of this in~ention, contain
other than carbon in a ring or chain otherwise cGll.posed of carbon atoms.
~Ieteroatoms include sulfur, oxygen, nitrogen, and encompass substituents as
pyridyl, furyl, thienyl and im;dazolyl. In general, no more than two, preferablyno more than one, non-hydrocarbon substiluent will be pl'CSe,llt for every ten
carbon atoms in the hydrocarbyl group; typically, there will be no non-
hydrocarbon substituents in the hydr~carbyl group.
Preferably the hydrocarbyl group is an alkyl group. Typically the alkyl
group will contain at least 6 carbon atoms, and preferably 7 to 1000 carbon
CA 02235835 1998-04-24
atoms,~ore 'p'r'efe'rably '7to-24 car~bon atoms, and alle.llati~ely, preferably 18
to 50 carbon atoms. In another embo~im~nt the alkyl group is a polymeric
group such as a polyethylene, a pol~ropylene, or a polybutene group, or an-
other homo- or co-polyalkylene group. The alkyl substituents can be a mixture
5 of alkyl groups of different chain lengths, as is indeed often the case with
commercially available materials. The alkyl groups, in any case, can be derived
from either linear or branched olefin ~ Pnts; linear are sometimes l.refel.~d,
although the longer chain length ~n~tçri~l~ tend to have increasing proportions
of br~n~-hing. A certain amount of b~ c~ g apl,e~s to be introduced via a
10 rearrangv.l.ent mech~ni~m during the alkylation process as well.
The hy~loc&-lJrl group can be derived from the corresponding olefin; for
example, a C26 allcyl group is derived from a C26 alkene, preferably a l-alkene, a
C34 alkyl group is derived from a C34 alkene, and mixed length groups are
derived from the corresponding ~ lu.e of olefins. When the hydrocarbyl group
15 is a hydrocarbyl group having at least about 30 carbon atoms, however, it is
frequently an aliphatic group (or a mixture of such groups) made from homo- or
interpolymers (e.g., copolymers, terpolymers) of mono- and di-olefins having 2
to 10 carbon atoms, such as ethylene, propy}ene, b.-lcne-l, isobutene, butadiene,
isoprene, l-he~r~n~, and 1-octene. ~4liph~tjc hydrocarbyl groups can also be
20 de~i~,ed from halogenated (e.g., chlorinated or bror~ Ated) analogs of such
homo- or interpolymers. Such groups can, ho..ever, be derived from other
sources, such as monomeric high molecular weight ~lken~s (e.g., l-tetracontene)
and chlorinated analogs and hydrochlorinated arialogs thereof, aliphatic petro-
leum fractions, particularly paraffin waxes and cracked and chlorinated analogs
25 and hydrochlorinated analogs thereof, white oils, synthetic alkenes such as those
produced by the Ziegler-Natta~ process (e.g., poly(ethylene) greases) and other
sources known to those skilled in the art. Any ~nsatu~alion in the hydrocarbyl
groups can be reduced or elimins~teA if tesired, by hydrogenation according to
procedures known in the art. ~alion by routes or using materials which are
30 s;~bst~nti~!ly free from chlorine or other halogens is sometimes preferred for
environl~ tal reasons.
More than one such hydrocarbyl group can be present, but usually no
more than 2 or 3 are L~iesellt for each aroll.atic nucleus in the aromatic group.
Most typically only 1 hydrocarbyl group is p~ese.lt per aromatic moiety, particu-
35 larly where the hrdrocall,~l-subslilul~d phenol is based on a single benzene
ring.
: CA 02235835 1998-04-24
'
-Thé ~nA-~time~ t o~lyd.oc~l,~l group to the aromatic moiety of the first
reactant of this invention can be accomplished by a number of techniques well
known to those skilled in the art. One particularly suitable techniqu¢ is the
Friedel-Crafts reaction, ~lel~in an olefin ~e.g., a polymer cont~ining an olefinic
5 bond), or halogenated' or hydrohalogenated analog thereof, is reacted with a
phenol in the presence of a Lewis acid catalyst. Methods and conditions for
carrying out such reactions are well known to those skilled in the art. See, forexample, the ~ cl~ssion in the article entitled, "Alkylation of Phenols" in "Kirk-
Othmer Encyclopedia of Chemical Technology", Third Edition, Vol. 2, pages
10 65-66, Interscience Publishers, a division of John Wiley and Company, N.Y.
Other equally appropliate and convel~ient techniques for Att~chin~ the hydrocar-bon-based group to the aromatic moiety will occur readily to those skilled in the
art.
The second component which reacts to form the anti-fouling compound
15 of the ple,Sellt invention is a linking group or linking reagent. Typical linkin~
agents include aldehydes or ketones or a ~*a_live equivalent of aldehydes or
ketones. These are well-lcnown, cGll~ereially available materials, being repre-
sented by the formula R,~(=O)-R2. In ketones, both R~ and R2 are hydrocar-
byl ~ro~s; in aldehydes, at least 1 of Rl and R2 will be hydrogen; the other can20 be either hydrogen or hydrocarbyl. If the linkit~ group is derived from a
ketone, preferably at least one asld preferably both of the R groups will be a
lower alkyl group, having, for instance, 1 to 6 carbon atoms. If the linking
group is an aldehyde, it will preferably be an aldehyde of 1 to 12 carbon atoms.Suitable aldehydes thus have the general formula RC(O)H, where R is prefera-
25 bly hydrogen or-a hydrocarbyl group, as described abo~e, although in all cases
R can include other functional groups which do not inte.~.e with the condensa-
tion reaction (described below) of the aldehyde with the hydro~aro.llatic
compound. This aldehyde preferably co~tains 1 to 12 carbon atoms, more
preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms.
30 Such aldehydes include form~l~1ellyde, acetaldehyde, propionaldehyde, butyral-
dehyde, isobutyraldehyde, pentAn~ldehyde~ caproaldehyde, benzaldehyde, and
higher aldehydes. Monoaldehydes are plefe.led. The most preferred aldehyde
is formaldehyde, which can be supplied as a solution, but is more commonly
used in the polymeric form, as palafollllaldehyde. Palafoll~laldehyde may be
35 considered a reacti~re equivalent of, or a source for, an aldehyde. Other reactive
CA 02235835 1998-04-24
- 11
equivaknts may i~clude~ydrates, alcoholates, or cyclic trimers of aldehydes.
Reactive equivalents of ketones include the hydrates and alcoholates.
The hydrocarbyl phenol and the linking cG,lll)ou~ld (e.g., aldehyde) are
generally reacted in relative amounts ranging fIom molar or equivalent ratios ofphenol:linkil ~ compound of 2:1 to 1:1.5. Preferably approximately equal molar
arnounts will be employed, up to a 30% molar excess of the linkinp compound
(calculated based, for instance, on aldehyde monomer rather than oligomer or
polymer). When an aldehyde-is used as the linking compound, the amount of
the aldehyde is preferably S to 20, more preferably 8 to 15, percent greater than
the hydrocarbyl phenol on a molar basis. The components are reacted under
conditions to lead to oligomer or polymer formation. The molecular weight of
the product will depend on fealul~s including the equivalent ratios of the reac-tants, the tc.llpc~ e and time of the reac~on, and the impurities present. The
product can ha~e from 2 to 100 ~ro~alic units (i.e., the substituted aromatic
phenol monomeric units) ~reseni ~nlepeali~lg") in its chain, preferably 2 to 70
such units, more preferably 2 to 50, 39, or 14 units, and most preferably 2 to 12
units.
The hydrocarbyl phenol and the aldehyde are reacted by mixing the
alkylphenol and the aldehyde in an al)prol~l;ate amount of diluent oil or, op-
tionally, another solvent such as an aromatic solvent, e.g., xylene, in the pres-
ence of an acid such as sulfuric acid, a sulfonic acid such as an alkylphenylsul-
fonic acid, para-toluene sulfonic acid, or n~eth~ne sulfonic acid, an organic acid
such as glyoxylic acid, or Alnb~ lTM catalyst, a solid, macroporous, lightly
crosslinked sulfonated poly~lylene-divinylbenzene resin catalyst from Rohm
and Haas. The mixture is heated, generally to 90 to 160~C, preferably 100 to
150 or to 120~C, for a suitabIe time, such as 30 minutes to 6 hours, preferably 1
to 4, hours, to remove water of condellsation. The time and tempeial.lre are
correlated so that reaction at a lower tenlpe.~lu~ will generally require a longer
time, and so on. ~etermining the exact conditions is with;n the ability of the
person skilled in the art. If desired, the reaction mixture can thereafter be
heated to a higher t~n~er&l,lle, e.g., 140-180~C, preferably 145-155~C, to
further drive off volatiles and move the reaction to completion. The product canbe treated with base such as NaOH if desired, in order to neutralize the strong
acid catalyst and to prcpare a sodium salt of the product, if desired, and is
thaeafler isolated by con~ell~ional techniques such as filtration, as ap~ropfiate.
CA 02235835 1998 - 04 - 24
12
T~ïe lir~ed produc~~~will Co~ill a linking group which, when prepared
with an aldehyde or ketone, will conlaill an alkylene linking group. In the
simplest case, when the linking agent is formaldehyde, the alkylene linking
group will be a methylene group. If an alkyl-su~sliluled aldehyde is used, e.g.,5 RCHO, the linking group will generally be an alkyl-sub~liLuled methylene
group, that is, a l,l-alkylene group, -CHR- . If a ketone is used, RC(O)R', the
linking group will be -CRR'-, although for steric reasons the formation of such
linkages is less facile than those pr~pared from aldehydes, and particularly,
forrnaldehyde.
The product of this reaction of hydrocarbyl substituted phenols with
formaldehyde can be generally regarded as comprising polymers or oligomers
having the following 1~ peating slluclule:
OH
~CH2
and pos;tional isomers thereof. However, a portion of the formaldehyde which
15 is preferably employed may be incol~o~tcd into the molecular structure in theform of substituent groups and linking groups such as those illustrated by the
following types, including ether linkages and hydroxymethyl groups:
OH H
O, ~R4
OH o,CH2 o
R~(CH 2~ 1RH~
R2 2
CA 02235835 1998-04-24
13
OH H
R~CH2~o~C~ xR
R2 Rs
Alle~llali~ely, the hydrocarbyl-s-lk~ .te~ aromatic moieties can be linked
by a sulfur atom, or by a chain of up to about 4 sulfur atoms, preferably up to 2.
Sulfur linkage can be provided by he~ti~ the hydrocarbyl phenol with a sulfuriz-ing agent such as elemental sulfur or a reacli~e equivalent such as a sulfur halide
such as SCl2 or S2Cl27 at 50-250~C, and usually, at least 160~C if elernçnt~l sulfur
is used, optionally in the ~sence of a suitable diluent. It is generally plerell~d to
employ 0.5 to 2.5 moles of phenol per equivalent of sulfurizing agent. The
equivalent weight of a sulfilr halide is considered to be half its molecular weight,
since one mole thereof reacts with two moles of phenol. The equivalent weight ofsulfur is considered to be equal to its molecular weight since two atoms of sulfur
react to provide one link~e and one molecule of H2S. Particularly if a sulfur
halide is used as the sulfurizing agent, it is frequently desirable to use an acid
acce~lor such as sodium hydloxide or sodium acetate to react with the hydrogen
halide evolved. Reaction conditions when SCl2 is the sulfurizing agent generallyinclude heati~g to, e.g., 75-110~C for 2 to 3 hours. P~&alion of sulfur-linked
phenols is described in greater detail in U.S. Patent 3,951,830, among others.
When elern-ont~l sulfur is used as the linking agent, a variable amount of polysul-
fide bridging is sometimes obtained beeause of the oligomeric nature of the
sulfilr.
Finally, the aromatic moieties can be linked by a direct carbon-carbon
bond bct~.~ el~ the rings.
In a prefe.l~d embodiment, the salt of the ~lese.ll invention is a salt of a
compound p~ cip~lly re~ sel~te~l by the structure
CA 02235835 1998-04-24
14
OH OH OH
T~ ,X~,X~,T
and positional isomers thereo~ In this structure each R is independently a
hydrocarbyl group as defined above, e.g., generally cont~inine 6 to 1000 carbon
atoms, each X is for the most part -CH2- or a sulfur bridge, each T is selected
5 from hydrogen, hydrocarbyl, hydroxymethyl, or formyl, and n is a number from
Oto 10.
The aforedescribed con~lçn~stion product is supplied as a salt. The salt
can be partially neutralized, fully neutralized, or ove.~ascd. Neutral salts arethose in which all or subst~nti~lly all of the acidic functionality is reacted with a
10 basic material by conventional means to form the salt. Suitable cations include
metals, ammonium, and amine ions, incl~ing qllA~e~ ammonium ions.
Suitable metals include alkali met~lc, alkaline earth metals, other monovalent
and polyvalent metals such as al~lminnm and transition met~l~, and preferably
divalent (doubly ~ positively charged) metals such as magnssiurn~ calcium,
15 sllolltilllll, barium, tin, lead, iron (II), copper (II), and zinc, most preferably
calcium or m~g~sium.
Partially neutralized salts of the pfes~nt invention are those in which not
all of the acidic group are reacted~with the basic material. It is l~refelled that
the acidic groups be at least 50 pelce~t neutralized, preferably at least 70 per-
20 cent, and more prefe.ably at least s~ ly completely neutrali~d.
Ovc.l,ased salts, sometil~es refe~i~.d to as ;,u~e.l,ased salts, are generallys,ingle phase, homogeneous Newton;an systems characterized by a metal content
in excess of that which woult be l.le3ent for neutralization according to the
stoichiometry of the metal and the particular acidic organic compound reacted
25 with the metal. The overbased materials are prcpalcd by re~ctin~ an acidic
material (typically an inorganic acid or lower carboxylic acid, preferably carbon
dioxide) with a mixture comprising an acidic organic compound, a reaction
medium comprising at least one inert, organic solvent (such as mineral oil,
n~phth~, toluene, xylene) for the acidic organic material, a stoichiometric excess
CA 02235835 1998-04-24
of a metal base, aria~a pro~noter suc~ as a phenol or alcohol. The acidic organic
material in the l3.esellt invention will be the phenolic product described in detail
above; it should have a sufficient n~lmber of carbon atoms in its hydrocarbyl
substituents to provide a degree of solubility in oil or the other organic solvent.
S The amount of excess metal used in the prep~alion of the overbased
material is commonly e~ressed in terrns of metal ratio. The term "metal ratiol'
is the ratio of the total equivalents of the metal to the equivalents of the acidic
organic compound. A neutral metal salt has a metal ratio of one. A salt having
4.5 times as much metal as presellt in a normal salt will have metal excess of 3.5
10 equivalents, or a ratio of 4.5. For use in the ~rc3ellt invention, the salts are not
particularly limited as to metal ratio, although generally salts with a metal ratio
of 0.5 (or even as low as 0.1) to 20 are suitable, and preferably with a metal
ratioofO.7toS,orl.Oto3.5,orl.5to3.
O~e.based materials generally and the processes for preparing them are
15 well known to those skilled in the art. Patents describing techniques for m~kinE~
basic salts of sulfonic acids, c&rl~lic acids, phenols, phosphonic acids, and
mixtures of any two or more of these include U.S. Patents 2,501,731; 2,616,905,
2,616,911; 2,616,925; 2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162,
3,318,809; 3,488,284; and 3,629,109. These techniques can be read;ly modified
20 by those skilled in the art to prepar~ ove.l,ased phenolic compounds suitable for
the prcsellt invention.
The detailed chemical and physical structures of the overbased and
neutralized materials off the presellt invention are not precisely known. Thus it
is not nccess~.ily certain whether the phenolic OH groups are entirely neutral-
25 ized, as opposed to existing as a complex i~ e of the acid (phenolic) form
with the basic material. Thus the terms "salt" and "ove.b~scd salt" and the like,
as used herein, are explicitly inten~le~ to encompass these complex forms and
any other as yet unidentified products which may be pres~nt, as well as the
con~e..lional salt forms.
30 Other A~iitives
The compositions employed in *is invention may conhin minor amounts
of other components. The use of such components is optional and the presence
thereof in the compositions of this invention will depend on the particular use
and level of performance required. Thus these components may be included or
35 excluded. Additives that may optionally be used include, for example, deter-
gents, dis~.sants, oxidation inhibiting agents (which can function as chain
te-.-lin~ion agents which can i~hibit undesired pol~...c.;~lion in petrochemical
CA 02235835 1998-04-24
16
or hydro'carbon 'process~-streams), including phenylenediamine compounds,
phenolics such as ortho-te,lb~ d-para-methoxyphenol, quinones such as terti-
ary-butylc~teçhol, and sulfur/amine col-lAinil-g materials such as dialkyldithio-
carb~m~tes, corrosion inhibitors, such as su~sl;l~l~e~ ~mi~es, e.g., tetrahydro-S pyrimidene compounds, reaction products of alkylene polyamines with aliphaticcarboxylic acids and'optionally a lower aldehyde, ~lk~line earth metal salts of
oil-soluble alkylbenzenesulfonic acids, amine salts of oil-soluble alkylnaphtha-lenesulfonic acids, dimercaptothi~ 7~leg~ alkoxylated derivatives of alkyl
phenols, reaction products of tallowamines and methylacrylate or acrylic acid,
10 or the reaction product of fatty acids and poly~mines; metal passivating agents
(i.e., metal deaclivator~ for sueh metals as copper or iron) such as N,N'-
disalicylidene-1,2-cycloh~ nç~i~mine, sodium N,N'-ethylenebis(2,5-sodium
sulfocarolate)gl~ci~ate, dim~c~t~ f~le de.i~dlives, and reaction prod-
ucts of an alkylphenol, an aldehyde, and a polyamine. A more extensive list of
15 oxidation inhibiting agents, corrosion inhibitors, and metal deactivators is found
in U.S. Patent 4,927,519. Zinc salts of dithiophosphoric acids, also referred toas zinc dithiophosphates, may also be piesellt, although they are often omitted
due to their pe.~cG;~ed contribution to fouling. Pour point deplegsing agents,
extreme pl~,SsuLc agents, viscosity i~ ro~,ers, and anti-wear agents may be
20 present if desired, although such are not normally prcse.ll in antifoulant com-
positions.
Additive ConrF.-t.ates
The various additives described herein, including the salt of the linked
hydrocarbyl-substiluled hydlo~y&~omatic material, can be added directly to the
25 hydrocarbon process streams. Alte~ lively, however, they can be diluted with a
sllbst~nti~11y inert, normally liquid organic diluent such as mineral oil, naphtha,
ben7e~e, toluene or xylene, to form an additive concellh~te. These concentlates
usually compAse 0.1 to 80% by weight, Ll~quelllly from 1% to 10% by weight,
more often from 10% to 80% by weight, of the compositions of this invention
30 and may contaill, in addition, one or more other additives known in the art or
described hereinabove.' Conce.lhalions such as 15%, 20%, 30% or 50% or
~ higher may be employed. Additive concenlldaes are prep~red by mixing to-
gether, often at elevated temperature, the desired components.
The ~ ro~rbon Process ~;:trf~ .c
The above-described composition is used as an antifoulant for controlling
the formation of fouling deposits in a hydrscarbon process stream during proc-
essing th~eof at elevated te.llpelalules. Such hydrocarbon streams include
:
CA 02235835 1998-04-24
(
17
petrokum oils'~~including~~rude oils, fractions of crude oil, such as naphtha,
kerosene, jet fuel, diesel fuel, residual oil, vacuum gas oil, or vacuum residual
oils (Bunker C fuel3, and other feed stocks which are heavy in nature, such as
atmospheric pipestill residuum, catalytic cracker resituum, and vacuum distil-
lation residuum. Also included are naturally sourced and partially refined oils,including partially processed petroleum derived oils. Also included are alkane
processes streams such as those wherein ethylene and propylene are obtained.
Also included are olefininc or n~phth~nic process streams, aromatic hydrocar-
bons and their derivatives, ethylene dichloride, and ethylene glycol. Among
the important units of, for example, an oil lefinel~ where the use of the antifou-
lant of the present invention can be employed are crude unit preheat exchanger,
crude unit ~acu~l, resid exchanger, crude unit vacuum ~ Sill~tion heater and
resid, fluid catalytie cracker preheat, fluid catalytic cracker slurry pumparound,
delayed cokor preheater and rulnLcc, fluid coker, visbreaker, hydrotreater,
hydrocracker, reboilers, hydrodesul~~ eis, heat exchangers, hot separators,
pumpalound circuits, and process strearn tubes.
The proces~in~ of such streams is often conducted at a temperature of
40~C to 820~C, preferably 260~C to 580~C. It is noted that the upper limits of
the lelllpelal~res reported here-and elsewhere in this specification and in the
elaims do not r.çce55~11y indicate the ten~eralul~ of the bulk of the material in
the process strearn. Rather, they ,epl~es~lll the contact tempcldlule of the proc-
ess stream at a metal surface, where fouling typically occurs.
The compositions of the - pleSent invention are employed in minor
amounts in the hydrocarbon process streams in the pleSent invention, often
amounts ranging from 1 to 5000 parts per million, preferably 3 to 1000 parts permillion, and more preferably 10 to 500 parts per million, e.g., 50-100 parts permiilion. The compositions can be added to hydrocarbon process streams by
mixin,~, addition, metering, or other conventional means.
F.X~1~qPT ~.~
Materials used in the examples are as follows:
F.~ ple A
Methylene-coupled~ dodecylphenol, partially neutralized with calcium,
having a metal ratio 0.85, prepared in a concentration of about 50.3% active
chemical in diluent oil and having a total base number (to bromophenol end-
point, "TBNn) of 90 (in diluent oil), pr~pared by a process more fully describedin U.S. Patent 3,256,183. -
CA 02235835 1998-04-24
18
F.~A..~yle ~
Methylene-coupled heptylphenol, partially neutralized with calcium,
having a metal ratio 0.80, prc~a;ed in a concehllation of about 32.5% active
chemical in diluent ~oil and ha~ing and a TBN of 65 (in diluent oil), prepared as
5 in Example A.
F.x~le C.
Sulfur-coupled dodecylphenol, overbased with magnesium, having a
metal ratio of 2.30, l>rel)ared as about 59% active chemical in diluent oil, con-
taining 2.5% sulfur and having a TBN of 90 (both measured in diluent oil),
prepared by a process more fully described in U.S. Patents 3,372,116 and
3,410,798.
F.Y~ e n.
Sulfur-coupled dodecy}phenol, overbased with calcium, having a metal
ratio of 1.10, pr~l3~c~ as about 45.7 l~reen~ active chemical in diluent oil,
co~t~ining 3.2% sulfur and having a TBN of 90 (both measured in diluent oil),
prepared generally as in Example C.
FY~ ple F.
SuIfur-coupled dodecylphenol, overbased with calcium, having a metal
ratio of 1.10, pr~ared as about 50.2% active chemical in diluent oil, containing3.7% sulfur and having a TBN of 90 (both measured in diluent oil), prepared
generally as in Example C.
F.Y~n~ple F.
Sulfur-coupled dodecylphenol, overbased with calcium, having a metal
ratio of 3.5~, piel,a~et as about 56.6% active chemical in diluent oil, cont~qinin~
3.2% sulfur and having a TBN of 255 (both me~ured in diluent oil), ~l~aled
generally as i~ Example C.
F.Y~rr~le G.
Sul~ur-coupled dodecylphenol, o~ ased with calcium, having a metal
ratio of 2.30, plepared as about 62.2% active chemical in diluent oil, containing
2.6% suifur and having a TBN of 200 (both measured in diluent oil), prepared
generally ss in Example C.
F.Y~le H.
An overbased phenate similsr to that of Exsrnple F, avilable commer-
ciallly from Chevron/Oronite.
Ssmples of the foregoillg m~teri~l~ are tested in a Hot Liquid Process
Simulator manufsctured by Alcor Petroleum Instruments, Inc., of San Antonio,
Texas. Each additive is diluted with a heavy aromatic n~phth~ to approxim~tely
CA 02235835 1998-04-24
19
25-% ~a~tlve c~iemical an~td~le~l to~various feedstocks at the dosage indicated
below, reported as part per million active chemical. During testing, a heater
tube is ~n~int~ined at a constant le~lp~ralul~, and a flow of fluid from a Parr
bomb (under nitrogen pres~ e of 4.5-5.5 MPs [650-800 psig]) is maintained
5 around the tube. As fouling deposits accumulate, heat transfer efficiency fromthe heater tube to the fluid decreases and l~lper~luie of the fluid at the outlet
correspondingly decreases. The extent of fouling of the tube is measured by the
dccrease in fluid outlet tem~perature of a sample under investigation as compared
to the decrease caused by the untreated feed stock. In a given test, before
10 significant fouling deposits accumulate, the "fluid out" te~ >elatUle achieves a
maximum teml,cralul~, Tm~ which is used as a ref~ ce. The fluid out tem-
el~lluic decreases as fouling deposits accumulate on the heater tube. Thetemper~lulc of the fluid out is plotted as a function of time, and the area of the
plot above the actual ten~el~lule plot and below the T~AX line is designated the15 fouling area, FA. When no antifouling chemical is added, the area is referred to
as FAbl~nk- The fouling area of a test sample which contains an antifoulant
chemical is r~fclled to as FAChem The l,~.cent protection provided by an anti-
foulant is calculated as
% Protection = 100~/O X (FAbl-nk FAChem) ~ FAblank
20 Experimental details and results are shown in the following table:
ppm Rod Feed Test Baseline
Addi- (act- Temp flow duration ~ area; % Pro-
Ex Feed tive~ ive) ~C m~min hr - (~, %)tection
Rl ~- ~s~heric residua -- 0 560 3 3 2048(12)
from Gulf Coast
refinery
A 250 " ~ n ~ 50
2 " B 250 " " n ~ S8
3 " C 250 " n ~ 35
4 " D 250 " " N 27
5, " E 250 " ~ n ~ 40
R2 ~ _ 0 550 4
6 ~ A 125 " ~' " " 24
7 " B 2S0 " n n 3
8 " B 125 " ~ n ~ 73
9 " C 125 " " " " 38
" D 125 n n n ~ 17
I l n E 125 n H ~ 23
12 " F 125 " " " " 23
13 " a 125 " " " " 41
14 " H 125 " n ~1 55
" B ~125 n ~ . n ~ 17
CA 02235835 1998-04-24
.16 n~ - 12S. n n N n 24
17 " B+G ~ n n ~ 21
+50
18 n B~G Z50 N n 1~ ~- 23
+250
19 " B+G S00 n ~ n 17
+500
R3 " -- 0 SS0 4 S 2463(30) --
" A 250 ~ n ~ 81
21 B 250 N n n 73
22 " G 250 " " n ~ 78
23 " A 250 n ~ 68
24 " A 250 " n " n 52
2S " G 250 n n n ~ 67
R4 vis-breaker feed from -- 0 S60 3 4 1815(13
Eu.upea~ refinery
(199S)
26 " B 7S6 " " " " 28 avg
27 n D 458 ~ ~ n n 9
28 " D 916 n n ~ n 36 avg
RS same (1996) -- 0 560 3 4 1903(32)
29 N B 190 N N n 59 avg
n B 380 N n n ~ 48
31 n B 760 n ~ N ~ 72
32 N A 250 n n ~ 52
R6 vis-broken tar from -- 0 540 3 4 3265(26)
Europc~ refinery
(1995)
33 n B 7S6 n n n ~ 31
34 n D 916 n ~ n ~ 5
R7 same (1996) -- 0 560 3 3 3694(31)
3S " B 9S N n n n 33
36 " B 125 n n ~ 49
37 B 190 N ~ 46
38 n B 250 N n 40
39 n A 2S0 n n n n 32
n D 12S " n n n 26
41 n D 250 " " n n 39 avg
R8 n _ 0 540 4 3 4225~22) --
42 n C 25v n n n n 45
43 " E 250 n n ~ n 72
R9 Mixture of atmos- -- 0 570 2.5 3 1174(12)
pheric and vacuum
residua from dirrc~
Gu}f Coast refinery
44 ~ C 2S0 n u ~ n -14
4S n D 500 n ~ n n ~ 16
46 n H S00 u n n n 14
47 n B 2S0 " " n ~ 19
48 n B 500 " " " n 13
49 N E 25a n ~ 16
S0 G S00 N n n 53 avg
CA 02235835 1998-04-24
R10 " - 0 ' 580 2.5 3 2185
51 " B 125 n ~ n ~ -6
52 " B 250 ~ ~ " " -11
Rll " - 0 5?0 2.5 3 1532(37~ -
53 " A 2S0 ~ n ~ ~ 40
54 n G 250 n ~ 53
55 ~ B+G i67 ~ N n ~ 14
+83
R12 " - 0 570 2.5 3 1494(19) -
56 " A 250 " " n ~ -14
57 n B 250 n ~ O
58 " G 250 n n n ~ 4
S9 " A+G 125 n n
+125
60 ~ B+G 167 ~ " n ~ 28
+83
R13 Same,~omrefine~ of - 0 575 3 3 2186
Ex.l
61 n A 250 " ~ " " 17
62 " B 250 n ~ 18
63 " G 250 n ~ 5
R14 " - 0 560 4 3 909(27)
64 " A 500 n ~ -2
65 " G 500 ~ n ~ n 9
R15 " - 0 570 3 3 1796(13) -
66 ~ B 500 n ~ " " 11
67 n B 1000 " ~ n ~ 25
68 " B 1250 ~ n n ~ 36avg
69 G 625 N n ~ 32
7o n G 1250 ~ ~ n n 41
71 D 1250 N n 41
72 " B+D 625 n n n ~ -2
+625
73 " B+G 600 n n . ~ ~- 39
+300
74 ~ B+G 800 n ~ n n 54avg
+400
75 " B+G 1000 n il ~ 40
- +500
76 ~ B+G 375+ ~- 1- ~ " 43
750
77 ~ B+G 600 " ~ ~ " 31
+900
a. From the synthetic example A-H as indicated
avg: average of multiple runs
~s: standard deviation of baseline measurements (where multiple baselines were
S run)
Each of the documents referred to above is incorporated herein by refer-
ence. Except in the Exarnples, or where otherwise explicitly indicated, all -
numerical qu&nlities in this desc~ ion spe~iryillg amounts of materials, reac-
CA 02235835 1998-04-24
22
tion ~itions, molecula~weights, jnumber-of carbon atoms, and the like, are to
be understood as modified by the word "about." Unless otherwise indicated,
each chemical or composition rere.lcd to herein should be interpreted as being acommercial grade material which may contain the isomers, by-products, deriva-
S tives, and other such materials which are normally understood to be present inthe commercial grade. However, the amount of each chemical component is
presented exclusive of any solvent or diluent oil which may be customarily
present in the commercial material, unless otherwise indicated. As used herein,
the c~lession "consisting essentially ofi' permits the inclusion of substances
10 which do not materially affect the basic and novel characteristics of the com-
position under consideration.
